1. Field of the Invention
The present invention relates generally to a cell assembly for evaluating the conductivity and permeability of proppants, and more particularly but not by way of limitation, to a plurality of vertically stacked cell units for determining the effects of fracturing fluids on the conductivity and permeability of proppants at simulated subterranean conditions.
2. Brief Description of the Prior Art
Knowledge of the characteristics of a subterranean formation is important for the efficient production of hydrocarbons from such a formation. In addition, knowledge as to the effect of fracturing fluids and additives on proppants injected into the formation is desirable so as to enhance hydrocarbon production. However, due to the complicated structure of many subterranean formations, and the interaction of materials injected into the formation (such as fracturing fluids, additives, proppants and the like, as well as the interaction of fracturing fluids on the proppant within the formation) the characteristics of the proppant permeability often change.
Many methods have heretofore been proposed to determine the effect of fracturing fluids on the conductivity and permeability of proppants. However, such prior art procedures have generally failed to take into account the combined effects of the formation temperature, closure stress, formation structure (i.e. hardness), residence fluids and injected fracturing fluid as well as other factors prevalent in subterranean formations. Therefore, it would be highly desirable if a cell assembly could be developed which would enable one to simulate downhole conditions in fracturing treatments of subterranean formations, and especially if such cell assembly would be capable of simulating fluid leakoff and providing shear history modeling for fracturing fluid systems. It is to such a cell assembly and a method for determining the effect of conductivity and permeability of proppants that the subject invention is directed.